What is the underlying physiological benefit of increasing citrate intake to prevent kidney stones?

Increasing citrate intake is beneficial for preventing kidney stones primarily because it inhibits stone crystallization. Citrate plays a critical role in the urinary system by binding to calcium and inhibiting the formation of calcium-based stones, which are the most common type of kidney stones. When citrate is present in the urine, it helps to keep calcium dissolved in the urine, reducing the likelihood of it precipitating and forming stones. Additionally, citrate can help maintain a supersaturated state of urine, where the dissolved substances do not exceed solubility limits, further preventing crystallization.

Enhancing urine pH, while it can be a factor in stone formation, is not the primary benefit associated with citrate consumption in this context. Citrate can indeed raise urine pH slightly, creating a more alkaline environment that is less favorable for the formation of certain types of stones, particularly uric acid stones, but the direct mechanism by which citrate prevents stones is its role in inhibiting crystallization processes.